FIXED_PKG package declaration

Standard instantiation of FIXED_GENERIC_PKG with the common defaults.

Use clause: library IEEE;
use IEEE.FIXED_PKG.all;
Source: ieee/fixed_pkg.vhdl in the IEEE 1076 OSR, tag 1076-2019
Apache License 2.0, © 2019 IEEE P1076 WG Authors
Length: 52 lines
VHDL revisions: Added in 1076-2008; updated through 1076-2019

Overview

FIXED_PKG is a single instantiation of FIXED_GENERIC_PKG with the standard defaults: round-nearest rounding, saturate on overflow, 3 guard bits, and warnings enabled. Use it directly when those defaults suit your model; instantiate FIXED_GENERIC_PKG yourself when you need different rounding or overflow behaviour.

Per §16.10 of IEEE Std 1076-2019, the instantiation declaration here represents the formal semantics of FIXED_PKG; the actual operator and conversion bodies live in FIXED_GENERIC_PKG’s body.

What's defined here

Generic instantiation: fixed_round_style => fixed_round, fixed_overflow_style => fixed_saturate, fixed_guard_bits => 3, no_warning => false
Underlying package: FIXED_GENERIC_PKG - the generic package this is an instantiation of.
Related: FIXED_FLOAT_TYPES (rounding and overflow enums)

VHDL source listing

doc

File header Comment block (43 lines)

lines 1–43

-- -----------------------------------------------------------------
-- 
-- Copyright 2019 IEEE P1076 WG Authors
-- 
-- See the LICENSE file distributed with this work for copyright and
-- licensing information and the AUTHORS file.
-- 
-- This file to you under the Apache License, Version 2.0 (the "License").
-- You may obtain a copy of the License at
-- 
--     http://www.apache.org/licenses/LICENSE-2.0
-- 
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
-- implied.  See the License for the specific language governing
-- permissions and limitations under the License.
-- 
--
--   Title     :  Fixed-point package (Instantiated package declaration)
--             :
--   Library   :  This package shall be compiled into a library
--             :  symbolically named IEEE.
--             :
--   Developers:  Accellera VHDL-TC and IEEE P1076 Working Group
--             :
--   Purpose   :  This packages defines basic binary fixed point
--             :  arithmetic functions
--             :
--   Note      :  This package may be modified to include additional data
--             :  required by tools, but it must in no way change the
--             :  external interfaces or simulation behavior of the
--             :  description. It is permissible to add comments and/or
--             :  attributes to the package declarations, but not to change
--             :  or delete any original lines of the package declaration.
--             :  The package body may be changed only in accordance with
--             :  the terms of Clause 16 of this standard.
--             :
-- --------------------------------------------------------------------
-- $Revision: 1220 $
-- $Date: 2008-04-10 17:16:09 +0930 (Thu, 10 Apr 2008) $
-- --------------------------------------------------------------------

library IEEE;

package fixed_pkg is new IEEE.fixed_generic_pkg
  generic map (
    fixed_round_style    => IEEE.fixed_float_types.fixed_round,
    fixed_overflow_style => IEEE.fixed_float_types.fixed_saturate,
    fixed_guard_bits     => 3,
    no_warning           => false
    );